Point-of-care inventory management system and method

ABSTRACT

A system and method are disclosed for controlling an inventory of point-of-care diagnostic devices. The inventory includes a main inventory and at least one subinventory. Each device has an ambient temperature shelf life. Data associated with the devices is entered, including: the current quantity and predetermined minimum quantity of devices in the main inventory; and the current quantity and predetermined minimum quantity of devices in the subinventory. A first timestamp is associated with each device when the device is transferred from the main inventory to the ambient temperature subinventory. The first timestamp is compared to a second timestamp prior to use of the device to determine whether the device&#39;s ambient temperature shelf life is exceeded. The current quantity of devices in the subinventory is updated in response to an event that causes a change in the current quantity of devices in the subinventory.

CROSS-REFERENCE TO RELATED APPLICATIONS

This is a continuation of U.S. patent application Ser. No. 13/051,520,filed Mar. 18, 2011, which is a continuation of U.S. Pat. No. 7,912,754,issued on Mar. 22, 2011, which is a division of U.S. Pat. No. 7,552,071,issued on Jun. 23, 2009, which is a continuation of U.S. Pat. No.7,263,501, issued on Aug. 28, 2007. Each of these applications isincorporated herein by reference in its entirety.

BACKGROUND

Field of the Invention

The present invention relates to a method and apparatus for inventorycontrol, specifically to disposable elements and general consumableitems that are used in a hospital or medical facility, and morespecifically to point-of-care sample analysis systems that use differenttypes of disposable devices.

Background Information

For hospitals, the recent introduction of point-of-care testingcapabilities has created unique requirements for inventory control. Theinventory control requirements arise from the use of multiple types ofdisposable sample testing devices at various locations within ahospital. The hospital must provide an adequate supply of each type ofdevice at each site of use. However, the hospital tries to be mindful ofthe cost of carrying excess inventory at each site. This is also truefor other locations where point-of-care testing occurs, such as militarycombat sites, cruise ships and nursing homes.

Certain sample testing devices have a finite shelf-life, in which theshelf-life may depend upon whether the sample testing device isrefrigerated or maintained at ambient or room temperature, e.g., roomtemperature for a hospital. For example, a blood testing device may havea shelf-life of six to nine months when refrigerated, or a limitedshelf-life of two weeks at ambient temperature. Because of thedifferences in shelf-life, a hospital will generally store devices at acentral refrigerated location, and deliver devices to specificdepartments as demand requires. These departments may or may not haveavailable refrigerated storage, which consequently affects the inventorythey will maintain. In certain departments, general storage may belimited, which will also affect what level of inventory they maintain.

Point-of-care sample analysis systems are generally based on a re-usablereading apparatus that performs sample tests using a disposable device,e.g., a cartridge or strip, that contains analytical elements, e.g.,electrodes or optics for sensing analytes such as, for example, pH,oxygen and glucose. The disposable device can optionally include fluidicelements (e.g., conduits for receiving and delivering the sample to theelectrodes or optics), calibrant elements (e.g., aqueous fluids forstandardizing the electrodes with a known concentration of the analyte),and dyes with known extinction coefficients for standardizing optics.The reading apparatus contains the electrical circuitry and othercomponents for operating the electrodes or optics, making measurements,and doing computations. The reading apparatus also has the ability todisplay results and communicate those results to laboratory and hospitalinformation systems (LIS and HIS, respectively), for example, via acomputer workstation. Communication between the reading apparatus and aworkstation, and between the workstation and a LIS, can be via, forexample, an infrared link, a wired connection, wireless communication,or any other form of data communication that is capable of transmittingand receiving electrical information, or any combination thereof.

One benefit of point-of-care sample testing systems is the eliminationof the time consuming need to send a sample to a central laboratory fortesting. Point-of-care sample testing systems allow a nurse, at thebedside of a patient, to obtain a reliable, quantitative, analyticalresult, comparable in quality to that which would be obtained in alaboratory. In operation, the nurse selects a device with the requiredpanel of tests, draws a sample, dispenses it into the device, optionallyseals the device with, for example, a snap-closure, and inserts thedevice into the reading apparatus. While the particular order in whichthe steps occur may vary between different point-of-care systems andproviders, the intent of providing rapid sample test results close tothe location of the patient remains. The reading apparatus then performsa test cycle, i.e., all the other analytical steps required to performthe tests. Such simplicity gives the physician quicker insight into apatient's physiological status and, by reducing the time for diagnosis,enables a quicker decision by the physician on the appropriatetreatment, thus enhancing the likelihood of a successful patienttreatment.

In the emergency room and other acute-care locations within a hospital,the types of sample tests required for individual patients tend to vary.Thus, point-of-care systems generally offer a range of disposabledevices with different sample tests, or combinations of sample tests.For example, for blood analysis devices, in addition to traditionalblood tests, including oxygen, carbon dioxide, pH, potassium, sodium,chloride, hematocrit, glucose, urea, creatinine and calcium, other testscan include, for example, prothrombin time (PT), activated clotting time(ACT), activated partial thromboplastin time (APTT), troponin, creatinekinase MB (CKMB) and lactate. While devices typically contain betweenone and ten tests, it will be appreciated by persons of ordinary skillin the art that any number of test may be contained on a device. Forexample, a device for genetic screening may include numerous tests. Toillustrate the need for different devices, a patient suspected ofarrhythmia may require a device with a test combination that includes apotassium test, whereas a patient suspected of a diabetic coma mayrequire a device with a test combination that includes a glucose test.An emergency room will need to have sufficient inventory of both typesof device to ensure the supply meets the anticipated workload, whileseeking to limit the economic cost associated with carrying anunnecessarily high inventory.

A given hospital may use numerous different types of devices andaccordingly needs to maintain a combination of some or all of these ateach point-of-care testing location within the hospital. These locationscan include, for example, an emergency room (ER), a critical care unit(CCU), a pediatric intensive care unit (PICU), an intensive care unit(ICU), a renal dialysis unit (RDU), an operating room (OR), acardiovascular operating room (CVOR), general wards (GW) and the like.Other hospital locations can be used to deliver point-of-care testing,as can other non-hospital-based locations where medical care isdelivered, including, for example, MASH units, nursing homes, andcruise, commercial and military ships, and the like. FIG. 1 depicts anexample of monthly device consumption rates at different locations in ahospital versus the=different available device types. It will beappreciated by persons of ordinary skill in the art that the demand forparticular devices may vary significantly between locations within, forexample, a hospital.

Previously, inventory control of devices at the point-of-care relied ondirect human intervention. Typically, personnel in the emergency roomand/or other locations would call the hospital laboratory, wheredisposable devices are usually centrally stored to place an order.Alternatively, the hospital laboratory can control the disposable devicestorage at a central repository. The hospital laboratory would thenrequest additional devices of specific types to be delivered to therequesting department. The central repository would then arrange for thedevices to be delivered. Alternatively, a person from the laboratory,e.g., a designated point-of-care testing coordinator, would beresponsible for regularly visiting point-of-care testing locations,checking device inventory needs and ensuring that those needs are met.Because of the manual nature of this inventory control scheme, there areseveral opportunities for delay and possible human error.

Once devices are delivered from the central repository, the devices canbe stored at a convenient location, e.g., somewhere close to thepatient. The convenient location will vary by department, but caninclude, for example, at the patient bedside (e.g., when the readingapparatus is part of a patient monitoring system), at a nursing station,in an auxiliary room attached to a ward, in a satellite laboratoryattached to a critical care unit, and the like. One skilled in the artwill recognize that where devices are stored at the bedside, the devicesare unlikely to be refrigerated, whereas devices stored in a satellitelaboratory may be refrigerated.

Typically, devices are supplied by the manufacture to the hospital inboxes with a given number of units, e.g., 25 or 50 units, or any numberof units. The central repository in the hospital can supply thesedevices to the different departments in boxes or individually. Thus, theminimum inventory level for a department can be set in terms of thenumber of available unopened boxes of devices or on an absolute numberof available individual devices.

Current inventory control systems and methods for handling point-of-caredevice inventory place the end-user, usually a nurse, at the center ofthe process. Essentially, the end user had to log or visually monitorthe number of boxes of each type of device at their location and callthe central repository to order more, as they see fit. Alternatively, aperson from the laboratory was responsible for coordinatingpoint-of-care testing by making regular visits to each site and ensuringdevices are delivered when needed.

Thus, in creating the new environment of point-of-care sample testing,where a nurse performs sample tests at or close to the bedside of thepatient, many of the previous problems associated with delay due tosample transportation to a hospital laboratory for analysis have beensolved. The following patents relating to point-of-care sample testingare assigned to the same assignee as the present application: DISPOSABLESENSING DEVICE FOR REAL TIME FLUID ANALYSIS, Lauks et al., U.S. Pat. No.5,096,669; WHOLLY MICROFABRICATED BIOSENSORS AND PROCESS FOR THEMANUFACTURE AND USE THEREOF, Cozzette et al., U.S. Pat. No. 5,200,051;METHOD FOR ANALYTICALLY UTILIZING MICROFABRICATED SENSORS DURING WET-UP,Cozzette et al., U.S. Pat. No. 5,112,455; SYSTEM, METHOD AND COMPUTERIMPLEMENTED PROCESS FOR ASSAYING COAGULATION IN FLUID SAMPLES, Opalskyet al., U.S. Pat. No. 6,438,498; MICROFABRICATED APERTURE-BASED SENSOR,Davis et al., U.S. Pat. No. 6,379,883; APPARATUS FOR ASSAYING VISCOSITYCHANGES IN FLUID SAMPLES AND METHOD OF CONDUCTING SAME, Davis et al.,U.S. Pat. No. 5,447,440; REUSABLE TEST UNIT FOR SIMULATINGELECTROCHEMICAL SENSOR SIGNALS FOR QUALITY ASSURANCE OF PORTABLE BLOODANALYZER INSTRUMENTS, Zelin et al., U.S. Pat. No. 5,124,661; STATIC-FREEINTERROGATING CONNECTOR FOR ELECTRICAL COMPONENTS, Lauks, U.S. Pat. No.4,954,087; and REFERENCE ELECTRODE, METHOD OF MAKING AND METHOD OF USINGSAME, Lauks, U.S. Pat. No. 4,933,048.

However, new inventory management issues were created as a consequenceof the transition to point-of-care sample analysis.

SUMMARY OF THE INVENTION

A system and method are disclosed for controlling an inventory of aplurality of point-of-care diagnostic devices. The plurality of devicesincludes at least one type of device. Each device is configured toperform at least one sample analysis, and each device has a usablelifetime. The inventory includes a main inventory and at least onesubinventory. Each subinventory is associated with a point-of-carelocation. According to a first aspect of the present invention, theinventory control system comprises a data input interface for enteringdata associated with the devices and a data output interface fordisplaying data associated with the devices. The data can include acurrent number of at least one type of device in the main inventory anda predetermined minimum number of devices of that type in the maininventory, and can include a current number of at least one type ofdevice in the at least one subinventory and a predetermined minimumnumber of devices of that type in the at least one subinventory. Amemory stores data associated with the devices and stores steps of acomputer program to automatically update the current number of devicesin the at least one subinventory in response to an occurrence of anevent that causes a change in the current number of devices in the atleast one subinventory. For example, the event can include at least oneof (i.) a device from the at least one subinventory is used to performat least one sample analysis, (ii.) a device from the at least onesubinventory is transferred to another subinventory, and (iii.) a devicefrom the at least one subinventory exceeds the usable lifetime of thedevice. The inventory control system also includes a processor foraccessing the memory to execute the computer program.

According to a second aspect of the present invention, a method forcontrolling an inventory of a plurality of point-of-care sample analysisdevices, wherein the inventory includes a main inventory and at leastone subinventory, wherein the plurality of devices includes at least onetype of device, wherein each device is configured to perform at leastone sample analysis, and wherein each device has a usable lifetime,comprises the steps of: (i.) entering data associated with the devices,wherein the data includes a current number of at least one type ofdevice in the main inventory and a predetermined minimum number ofdevices of that type in the main inventory, and includes a currentnumber of at least one type of device in the at least one subinventoryand a predetermined minimum number of devices of that type in the atleast one subinventory, wherein each of the at least one subinventory isassociated with a point-of-care location; and (ii.) automaticallyupdating the current number of devices in the at least one subinventoryin response to an occurrence of an event that causes a change in thecurrent number of devices in the at least one subinventory.

According to a third aspect of the present invention, a method fordistributing devices having a finite usable lifetime, the devices beingcontained within an inventory of devices, comprises the steps of: (i.)determining an inventory level of devices in the inventory of a firstlocation, in response to an occurrence of an event that causes a changein a current number of devices in the inventory; (ii.) computing adevice usage rate for the first location; (iii.) determining an excessdevice differential based on the device usage rate and the inventorylevel, wherein the excess device differential represents the devicesthat will remain in the inventory at the expiration of the usablelifetime; and (iv.) transferring the excess device differential to asecond location. According to the alternative exemplary embodiment, apredetermined inventory level represents a minimum number of devicescontained in the inventory. The method can further comprise the steps of(v.) adjusting the predetermined inventory level based on the deviceusage rate, and (vi.) adjusting the predetermined inventory level basedon the excess device differential, thereby providing a dynamic andflexible approach to managing the inventory of devices having a finiteusable lifetime.

According to a fourth aspect of the present invention, an inventorycontrol system for controlling an inventory of a plurality ofpoint-of-care diagnostic devices comprises means for entering dataassociated with the devices. The inventory includes a main inventory andat least one subinventory. The plurality of devices includes at leastone type of device. Each device is configured to perform at least onesample analysis, and each device has a usable lifetime. The dataincludes a current number of at least one type of device in the maininventory and a predetermined minimum number of devices of that type inthe main inventory, and includes a current number of at least one typeof device in the at least one subinventory and a predetermined minimumnumber of devices of that type in the at least one subinventory, whereineach of the at least one subinventory is associated with a point-of-carelocation. The inventory control system comprises means for displayingdata associated with the devices and means for storing data associatedwith the devices. The inventory control system also comprises means forautomatically updating the current number of devices in the at least onesubinventory in response to an occurrence of an event that causes achange in the current number of devices in the at least onesubinventory.

According to a fifth aspect of the present invention, an inventorycontrol system for controlling the use of a plurality of point-of-carediagnostic devices in an inventory includes a data input interface forentering data associated with the devices. The data includes anindicator associated with at least one device. The plurality of devicesincludes at least one type of device, wherein each device is configuredto perform at least one sample analysis. The inventory includes arefrigerated inventory and an ambient temperature subinventory. Thedevices are stored in the refrigerated inventory and transferred to theambient temperature subinventory prior to use. Each device has anambient temperature usable lifetime. The inventory control systemincludes a memory for storing data associated with the devices and forstoring steps of a computer program to: (i.) receive an indication fromthe indicator associated with the at least one device, prior toperforming sample analysis using the at least one device; (ii.)determine, using the indication, whether the ambient temperature usablelifetime of the at least one device has been exceeded; and (iii.)prevent the at least one device from being used when a determination ismade that the ambient temperature usable lifetime of the at least onedevice has been exceeded. The inventory control system also includes aprocessor for accessing the memory to execute the computer program.

According to the fifth aspect, the indicator comprises a code associatedwith the at least one device. The memory stores steps of a computerprogram to: receive a first instance of the code associated with the atleast one device, when the at least one device is transferred from therefrigerated inventory to the ambient temperature subinventory; andassociate a first time indication with the first instance of the codeassociated with the at least one device. For the step of receiving anindication, the memory stores steps of a computer program to: receive asecond instance of the code associated with the at least one device,prior to performing sample analysis using the at least one device; andassociate a second time indication with the second instance of the codeassociated with the at least one device. For the step of determining,the memory stores steps of a computer program to compare the first andsecond time indications with the ambient temperature usable lifetime ofthe at least one device. According to another alternative exemplaryembodiment, the indicator is a time-temperature indicator.

According to a sixth aspect of the present invention, a method forcontrolling the use of a plurality of point-of-care diagnostic devicesin an inventory comprises the steps of: (i.) entering data associatedwith the devices, wherein the data includes an indicator associated withat least one device, wherein the plurality of devices includes at leastone type of device, wherein each device is configured to perform atleast one sample analysis, wherein the inventory includes a refrigeratedinventory and an ambient temperature subinventory, wherein the devicesare stored in the refrigerated inventory and transferred to the ambienttemperature subinventory prior to use, and wherein each device has anambient temperature usable lifetime; (ii.) receiving an indication fromthe indicator associated with the at least one device, prior toperforming sample analysis using the at least one device; (iii.)determining, using the indication, whether the ambient temperatureusable lifetime of the at least one device has been exceeded; and (iv.)preventing the at least one device from being used when a determinationis made that the ambient temperature usable lifetime of the at least onedevice has been exceeded.

According to the sixth aspect, the indicator is a code associated withthe at least one device, and the method comprises the steps of:receiving a first instance of the code associated with the at least onedevice, when the at least one device is transferred from therefrigerated inventory to the ambient temperature subinventory; andassociating a first time indication with the first instance of the codeassociated with the at least one device. The step of receiving anindication comprises the steps of: receiving a second instance of thecode associated with the at least one device, prior to performing sampleanalysis using the at least one device; and associating a second timeindication with the second instance of the code associated with the atleast one device. The step of determining comprises the step ofcomparing the first and second time indications with the ambienttemperature usable lifetime of the at least one device. According toanother alternative exemplary embodiment, the indicator is atime-temperature indicator.

BRIEF DESCRIPTION OF THE DRAWINGS

Other objects and advantages of the present invention will becomeapparent to those skilled in the art upon reading the following detaileddescription of preferred embodiments, in conjunction with theaccompanying drawings, wherein like reference numerals have been used todesignate like elements, and wherein:

FIG. 1 illustrates an exemplary table comparing monthly demand fordifferent devices at various hospital locations.

FIG. 2 is a block diagram illustrating an inventory control system forcontrolling an inventory of a plurality of point-of-care diagnosticdevices, in accordance with an exemplary embodiment of the presentinvention.

FIG. 3 is a block diagram illustrating an inventory control system forcontrolling an inventory of a plurality of point-of-care diagnosticdevices, in accordance with an exemplary embodiment of the presentinvention.

FIG. 4 is a flow chart illustrating the steps for maintaining anadequate supply of point-of-care diagnostic devices, in accordance withan exemplary embodiment of the present invention.

FIG. 5 is a flow chart illustrating the steps for monitoring theshelf-life of point-of-care diagnostic devices and replenishing a localinventory, in accordance with an exemplary embodiment of the presentinvention.

FIG. 6 is a block diagram illustrating a system, including multiplecentral data stations, wherein the point-of-care diagnostic devices aredistributed between departments that are controlled by the central datastations, in accordance with exemplary embodiments of the presentinvention.

FIG. 7 is a flow chart illustrating steps for determining whether toinitiate point-of-care diagnostic device re-dispatch, in accordance withan exemplary embodiment of the present invention.

FIG. 8 is a flow chart illustrating the steps for re-dispatching thepoint-of-care diagnostic devices between local inventories to reduceexcess devices, in accordance with exemplary embodiments of the presentinvention.

FIG. 9 is a flow chart illustrating steps for locking out point-of-carediagnostic devices, in accordance with an exemplary embodiment of thepresent invention.

DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS

A system and method are disclosed for controlling an inventory of aplurality of point-of-care diagnostic devices. The plurality of devicesincludes at least one type of device. Each device is configured toperform at least one sample analysis, and each device has a usablelifetime. The inventory includes a main inventory and at least onesubinventory. Each subinventory is associated with a point-of-carelocation. The inventory control system comprises a data input interfacefor entering data associated with the devices and a data outputinterface for displaying data associated with the devices. The data caninclude a current number of at least one type of device in the maininventory and a predetermined minimum number of devices of that type inthe main inventory, and can include a current number of at least onetype of device in the at least one subinventory and a predeterminedminimum number of devices of that type in the at least one subinventory.A memory stores data associated with the devices and stores steps of acomputer program to automatically update the current number of devicesin the at least one subinventory in response to an occurrence of anevent that causes a change in the current number of devices in the atleast one subinventory. For example, the event can include, but is notlimited to, at least one of (i.) a device from the at least onesubinventory is used to perform at least one sample analysis, (ii.) adevice from the at least one subinventory is transferred to anothersubinventory, and (iii.) a device from the at least one subinventoryexceeds the usable lifetime of the device. However, the event can be anytype of event that can cause a change in the current number of devices.The inventory control system also includes a processor for accessing thememory to execute the computer program.

Exemplary embodiments of the present invention provide an automatedsystem that ensures the maintenance of an adequate inventory ofdifferent types of disposable devices at multiple locations within ahospital. The disposable diagnostic devices can include, for example,blood analysis devices, urine analysis devices, serum analysis devices,plasma analysis devices, saliva analysis devices, cheek swab analysisdevices, or any other type of disposable diagnostic device that can beused for point-of-care sample testing. Other consumable items that areused in conjunction with the sample testing device or a readingapparatus can also be inventory items in the automated system, and thesystem is capable of providing an adequate inventory of those items, aswell. These consumable items can include, for example, syringes,vacutainers, swabs, needles, capillary tubes and collection devices,control fluids of different types, printer paper, batteries, and thelike. The automated system according to exemplary embodiments is capableof initiating automatic reordering of devices of various types from thesupplier, in relation to the consumption of devices at a giveninstitution. The automated system can redistribute devices betweenlocations within a hospital when a temporarily inadequate inventoryexists at a central location within a hospital, for instance where thereis an emergency medical situation causing a spike in demand for devicesin one particular department, or where supplies of new devices to thehospital from the supplier have been delayed by a transportationemergency.

Additionally, where devices have a fixed shelf life, the automatedsystem of the present invention ensures that inventory is supplied fromthe central inventory to ensure a high remaining shelf life in thecentral inventory, for example, using a first in, first out (FIFO) modeof operation. The automated system can be controlled by a computer andoptionally integrated into an existing laboratory information system anda hospital information system. The automated system of the presentinvention provides a user-friendly, and optionally substantiallyreal-time, display of inventory levels of each device type at eachlocation where devices are used or stored. Exemplary embodiments of thepresent invention can also provide a user-friendly tracking means forfollowing the different types of device consumption occurring in ahospital for the purpose of assisting the hospital in the analysis ofoperations, making forecasts, planning and the like.

Exemplary embodiments of the present invention can control the use of aplurality of point-of-care diagnostic devices in an inventory. Devicescan be stored in a refrigerated inventory and transferred to an ambienttemperature subinventory prior to use. Each device has an ambienttemperature usable lifetime. A device or a collection of devices can beprevented from being used when a determination is made that the ambienttemperature usable lifetime of the device or devices has been exceeded.The determination can be made, for example, by using a time-temperatureindicator associated with each device that indicates when the ambienttemperature usable lifetime of the device has been exceeded.Alternatively, a code, such as, for example, a bar code, RF tag or thelike, can be associated with a device or collection of devices. When thedevice or devices are transferred from the refrigerated inventory to theambient temperature subinventory, a first timestamp can be associatedwith the code. Prior to the use of the device or devices, a secondtimestamp can be associated with the code and can be compared to thefirst timestamp. The device or devices can be prevented from being usedif the time difference between the two timestamps exceeds the ambienttemperature usable lifetime of the device or devices.

These and other aspects of the present invention will now be describedin greater detail. FIG. 2 is a block diagram illustrating an inventorycontrol system for controlling an inventory of a plurality ofpoint-of-care diagnostic devices, in accordance with an exemplaryembodiment of the present invention. The system 100 includes a readingapparatus 102, a disposable device 104, a central data station 106 and abox of devices 108. The reading apparatus 102 can include, for example,a display, electronic memory and a keypad for manual data entry. Thedisposable device 104 can include, for example, a port for receiving apatient sample 110. The reading apparatus 102 can communicate with thecentral data station 106 using, for example, a wire, a wirelessconnection, an infrared link, an optical link, a network connection 112,114, or any other form of communication link that uses any form ofcommunication protocol to transfer information electronically.

The reading apparatus 102 can include a barcode reader 116 for readinginformation from a patient's bar-coded wristband 118, from a barcode 120on a device 104 or from any other item 122 (e.g., the box of devices108) used in conjunction with the reading apparatus 102. Other suchencoding arrangements can be used. For example, the reading apparatus102 can also include (either alternatively or in addition to the barcodereader 116) a radio-frequency (RF) identification device 124 that iscapable of identifying a RF tag 126 that is contained on or in eachindividual device or each box of devices 108.

According to another exemplary embodiment of the present invention, oneor more of the encoding arrangements can be based upon a binary codingpin array 128 of the type disclosed in, for example, jointly-owned U.S.Pat. No. 4,954,087.

The various encoding arrangements can convey relevant information suchas, for example, the identity of a specific device type, date andlocation of manufacture, manufacturing lot number, expiration date, aunique number associated with a device, coefficients for use by thereading apparatus 102 associated with the calculation of blood or othersample parameters and the like. The devices can be used for measurementsselected from groups such as, for example, amperometric, potentiometric,conductimetric, optical and the like. Other relevant information of thisgeneral type is well known in the medical manufacturing art, as is thetechnology for bar coding and barcode recognition.

For encoding on the basis of radio-frequency (RF) communication, thedevice 104 can include a tag on which one or more indications of, forexample, the refrigerator shelf life of the device 104, the ambienttemperature shelf life of the device 104, the age of the device 104, andthe like is located. Alternatively, rather than including numerouselements of relevant information on the tag, a single piece ofinformation, e.g., a lot number, can be included on the tag. The lotnumber can be any alphanumeric sequence or unique identifier that can beused to identify the device 104 and associate relevant information withthat device. For example, the lot number can be applied to a lookuptable or any other type of computer database located within or connectedto the reading apparatus 102 or any other computing system. Using thelookup table or computer database, relevant shelf life or other suchinformation can be associated with the lot number such that, based onthe lot number, the refrigerator shelf life, the ambient temperatureshelf life, the age of the device 104 and the like can be determined.

The technology for RF encoding and RF code recognition using RFidentification coded tags are known to those skilled in the art. A RFidentification device 124, 126 can comprise, for example, aself-contained, passively powered device with, for example, an antenna,memory, transmitter and the like in a package with dimensions of, forexample, a few millimeters. The RF identification device 124 can beimplemented on, for example, a printed circuit board with a serial portwith dimensions of, for example, about one square centimeter or more.Alternatively, the RF identification device 124 can be in the form of,for example, an application specific integrated circuit (ASIC) forintegration into an established system. However, the RF identificationdevice 124 can be implemented using hardware, firmware, or anycombination thereof, with the size of the device dependent upon themeans of implementation. The electronic components for RF encoding canbe selected to determine the proximity of the encoding element to thereceiving component for reliable transmission to occur. Such proximitycan range from, for example, a few millimeters up to a few meters,although the actual proximity will depend upon the choice of electroniccomponents. Optionally, the proximity can be set such that the exchangeof information occurs when the device 104 is inserted into the readingapparatus 102.

The aforementioned encoding arrangements differ in the amount ofinformation that can be conveniently transferred to the readingapparatus 102 and the required proximity between the reading apparatus102 and source of the information. For the binary pin array of U.S. Pat.No. 4,954,087, there is physical contact between the device 104 and thereading apparatus 102 and the data is limited by the number of availablepins, generally in the range of, for example, two to about twenty pins.For bar-coding, the user brings the barcode and reading apparatus 102into close proximity and at a specific orientation relative to eachother. However, the data contained in the barcode can be significantlygreater than the binary pin array. The RF encoding approach offers evengreater data capabilities without requiring the user to bring the device104 into a specific orientation with the reading apparatus 102 forsuccessful transmission.

The devices 104 can have a finite refrigerator and ambient temperatureshelf life. For example, the devices 104 can have a refrigerated usablelifetime in the range of, for example, about three months to threeyears, although the devices 104 could have any range of refrigeratedusable lifetime. The devices 104 can have an ambient temperature usablelifetime in the range of, for example, about three days to three months,although the devices 104 can have any range of ambient temperatureusable lifetime. Given that the devices 104 can have a finiterefrigerator and ambient temperature shelf life, there is a need toensure that expired devices 104 (i.e., the devices 104 that haveexceeded the refrigerated or ambient temperature shelf life) are notused.

In accordance with exemplary embodiments, the device 104 can include anindicator 111, such as, for example, a time-temperature indicator thatprovides an indication of whether the device 104 has expired. Forindicator 111, the device 104 can include temperature-sensing circuitry(e.g., hardware, firmware, or any combination thereof) for monitoringthe temperature of the device 104. When the temperature-sensingcircuitry included in device 104 determines that the temperature of thedevice 104 has remained within a certain range (e.g., ambienttemperature) for a period of time that is greater than a predeterminedthreshold (e.g., the ambient temperature shelf life), the circuitry canprovide an electrical signal to indicator 111 that causes the indicator111 to emit an indication (e.g., a flashing, blinking or steady light, achange in color, a sound, and the like) that the device 104 is expired.Alternatively, the temperature monitoring component can be based on aphysical or chemical change that is temperature dependant. This canresult in, for example, a physical or color change that is registered bythe reading apparatus 102. The temperature monitoring component can be,for example, a liquid crystal or mechanical device, for example, athreshold device with a wax seal that, when melted at a certaintemperature, releases a spring, or any other type of liquid crystal ormechanical device that is temperature sensitive and can register orotherwise indicate that the device 104 has expired based on temperature.

The temperature monitoring component can alternatively be a device thatacts as a time-temperature monitor with a threshold that equates to asafe, but variable, lifetime. In other words, the time-temperaturemonitor can either increase or decrease the lifetime of the device 104depending upon the temperature in which the device 104 is kept. Forexample, a device 104 that has been removed from a refrigerator and hasbeen maintained at a low ambient temperature (e.g., at or near therefrigerator temperature), for example, a military MASH unit during awinter deployment, can have a time-temperature indicator that permits,for example, one extra week of post-refrigerator shelf-life because ofthe low ambient temperature. Alternatively, the same MASH unit in adesert deployment in which the ambient temperature is high (e.g., wellabove the refrigerator temperature), can have a time-temperatureindicator that expires before one where the ambient temperature islower. However, those of ordinary skill in the art will recognize thatthe amount of increase or decrease in the lifetime of the device 104will depend upon the actual ambient temperature of the post-refrigeratorenvironment into which the device 104 is removed, and will thus varyaccordingly. As used herein, “refrigerated storage” generally refers tostorage in the range of about 36 to about 46 degrees Fahrenheit (about 2to about 8 degrees Celsius), and “room temperature storage” generallyrefers to storage in the range of about 64 to about 86 degreesFahrenheit (about 18 to about 30 degrees Celsius). Ambient storageconditions can be similar to room temperature storage, but can be in therange of about 36 to about 104 degrees Fahrenheit (about 2 to about 40degrees Celsius).

According to an alternative exemplary embodiment of the presentinvention, the device 104 or a collection of devices 104 (e.g., a box ofdevices 108) can be prevented from being used by comparing, for example,time indicators associated with the device 104 with the ambienttemperature usable lifetime of the device or devices 104. For example,each device or devices 104 can have a code, such as for example, a barcode, RF tag or the like, associated with the device or devices 104.When the device or devices 104 are transferred from a refrigeratedinventory to an ambient temperature subinventory, a first instance ofthe code associated with the device or devices 104 can be entered intothe reading apparatus 102 via the identification device associated withthe reading apparatus 102 (e.g., via barcode reader 116 or the like). Afirst time indication, such as, for example, a first timestamp, can beassociated with this first instance of the code by the reading apparatus102. Prior to performing sample analysis using the device or devices104, a second instance of the code associated with the device or devices104 can be entered into the reading apparatus 102 via the identificationdevice associated with the reading apparatus 102. A second timeindication, such as, for example, a second timestamp, can be associatedwith the second instance of the code by the reading apparatus 102. Thetime difference between the two timestamps can then be determined, andthis time difference can be compared to the ambient temperature usablelifetime of the device or devices 104. If the time difference exceedsthe ambient temperature usable lifetime of the device or devices 104,the device or devices 104 can be prevented from being used. For example,the operator can be notified that the device or devices 104 have expiredthrough visual means (e.g., a warning message is displayed on thedisplay of the reading apparatus 102, an warning light or indicatorblinks or otherwise flashes on the reading apparatus 102, or the like),audible means (e.g., a warning sound is played by the reading apparatus102), an electronic message relayed to the operator, central repository,or other entities through a computer or other network connection, or thelike.

Referring to the disposable device 104 and the patient sample entry port110, the device 104 can perform analyses on a range of sample types.These sample types can include, for example, arterial, capillary andvenous blood, plasma, serum, interstitial and spinal fluid, urine,bodily secretions and the like. Appropriate consumable items for use inconjunction with the device 104 are well known in the art. Theseinclude, for example, vacutainers, needles, capillary tubes andcollection devices, control fluids of different types, syringes, swabs,printer paper, batteries and any other consumable item that can be usedin conjunction with the device 104. The consumable items can also beused to facilitate introduction of the sample into the sample entry port110.

FIG. 3 is a block diagram illustrating an inventory control system forcontrolling an inventory of a plurality of point-of-care diagnosticdevices, in accordance with an exemplary embodiment of the presentinvention. The system 300 can include a central repository 302, areading apparatus 102, a local inventory of devices 305, and a device104. The central repository 302 can include a microprocessor 308. Themicroprocessor 308 can be any type of processor, such as, for example,any type of general purpose microprocessor or microcontroller, a digitalsignal processing (DSP) processor, an application-specific integratedcircuit (ASIC), a programmable read-only memory (PROM), an erasableprogrammable read-only memory (EPROM), an electrically-erasableprogrammable read-only memory (EEPROM), a computer-readable medium, orthe like.

The central repository 302 can also include computer memory, such as,for example, RAM 310. However, the computer memory of central repository302 can be any type of computer memory or any other type of electronicstorage medium that is located either internally or externally to thecentral repository 302, such as, for example, read-only memory (ROM),random access memory (RAM), compact disc read-only memory (CDROM),electro-optical memory, magneto-optical memory, or the like. Accordingto exemplary embodiments, RAM 310 can contain, for example, theoperating program for the central repository 308. As will be appreciatedbased on the following description, the RAM 310 can, for example, beprogrammed using conventional techniques known to those having ordinaryskill in the art of computer programming. The actual source code orobject code for carrying out the steps of, for example, a computerprogram can be stored in the RAM 310.

The central repository 308 can also include a database 312. The database312 can be any type of computer database for storing, maintaining, andallowing access to electronic information stored therein. For example,the database 312 can contain information relating to thresholdrequirements of the device 104 for each reading apparatus 102, e.g., theminimum desired number of devices 104 to be maintained in localinventory 305. The central repository 308 can also include acommunications port 314 with which the central repository 302 cancommunicate with the reading apparatus 102. The communications port 314can be any type of communications port through which electronicinformation can be communicated over a communications connection,whether locally or remotely, such as, for example, an Ethernet port, anRS-232 port, or the like. The central repository 302 can also include aninventory 315, which can be a physical repository of devices 104, otherconsumable items that can be used in conjunction with the devices 104,or the like.

The reading apparatus 102 can include a microprocessor 316 (e.g., anytype of processor). The reading apparatus can also include any type ofcomputer memory or any other type of electronic storage medium that islocated either internally or externally to the reading apparatus 102,such as, for example, RAM 318. According to exemplary embodiments, theRAM 318 can contain, for example, the operating program for the readingapparatus 102. As will be appreciated based on the followingdescription, the RAM 318 can, for example, be programmed usingconventional techniques known to those having ordinary skill in the artof computer programming. The actual source code or object code forcarrying out the steps of, for example, a computer program can be storedin the RAM 318.

The reading apparatus 102 can include a communications port 320 (e.g.,any type of communications port through which electronic information canbe communicated over a communications connection, whether locally orremotely) with which the reading apparatus 102 can communicate with, forexample, the central repository 302. The reading apparatus 102 can alsoinclude an input port 322 that, for example, allows insertion of thedevice 104 and is appropriately configured to receive the device 104.The reading apparatus 102 can also include a user interface 324. Theuser interface 324 can be any type of computer monitor or display deviceon which graphical and/or textual information can be displayed to a user(e.g., through a graphical user interface) and which allows a user toenter information (e.g., commands and the like) through, for example, akeyboard, a touch-screen, any type of pointing device, electronic pen,and the like. For example, the user interface 324 can be configured toreceive instructions from the operator of the reading apparatus 102.

According to exemplary embodiments, the local inventory 305 is arepository of physical items that can include, for example, the actualdevices 104 of one or more types of devices that are available to thereading apparatus 102. However, the local inventory 305 can also includeany other consumable item that can be used in conjunction with thedevices 104.

According to an exemplary embodiment, the number of devices 104 that areassociated with the local inventory 305 can be entered electronically,for example, through a scanning arrangement using a barcode reader, datatransmission from the central repository 302, or other electronic means.According to an alternative exemplary embodiment, the number of devices104 can be entered manually. The initial stock level can be set through,for example, an electronic notification, manual entry, applicationsumming notifications, and the like. With respect to an electronicnotification, the initial stock level can be set electronically by, forexample, a message from the supplier with an indication of the quantityand type of devices 104. With respect to application summingnotifications, when inputting the initial stock level, the number ofdevices 104 in each box 108 can be allocated based on a single scan ofthe box. For example, where each box 108 of devices 104 can have abarcode 122 (see FIG. 2) that identifies the type of the devices 104 andnumber of devices 104 in the box 108, the user can swipe the box 108past the barcode reader 116 located on the reading apparatus 102. Thenumber of devices 104 in the box 108 may be in the range of, forexample, 1 to 100. However, it should be appreciated that the number ofdevices 104 in the box 108 can vary, for example, with the size of thebox 108. Alternatively, the barcode reader 116 can be located on adepartmental central data station (CDS). If multiple boxes 108 of thesame device 104 type are being added to the department's local inventory305, then the user can swipe all the boxes, swipe the first box andmanually input the total number of boxes, or some combination inbetween. It should be appreciated by persons of ordinary skill in theart that application summing notifications can be manual or automatic,based on, for example, electronic notifications, as described above.

Alternatively, when the devices 104 arrive at a given department fromthe central repository 302, the boxes 108 can be scanned by, forexample, bar-code or RF means, thereby updating the departmental localinventory 305. The inventory information can be recorded in the CDS anda message can be optionally sent back to the central repository 302confirming that the correct devices 104 have arrived. The centralrepository 302, or a second location, can be, for example, a hospitalcentral laboratory store, or a general hospital store. In somecircumstances where the hospital is small, or there are supplyconstraints, the central repository 302 can be off-site, such as, forexample, a hospital supply company store or a device 104 and consumablesstore at a remote vendor location.

When a device 104 is consumed by the reading apparatus 102, it isdesirable to maintain an adequate supply of devices 104 available forfurther consumption by the reading apparatus 102. FIG. 4 is a flow chartillustrating the steps for operating the system 300 to maintain anadequate supply of devices 104, in accordance with an exemplaryembodiment of the present invention. First, the reading apparatus 102receives the device 104 at the input port 322 (block 402). The device104 can be received by any of the arrangements that have been described,including physical interface, barcoding, RF interface, infraredinterface, and the like. Upon receipt of the device 104, the readingapparatus 102 can communicate via COM port 320 to the central repository302 that the device 104 has been used (block 404). The centralrepository 302 can record the consumption of device 104 in the database312 (block 406). The central repository 302 can compare the number ofdevices 104 that are available in local inventory 305 to the readingapparatus 102 with a predetermined minimum inventory level for thereading apparatus 102 (block 408). Based on, for example, theconsumption rate for a device at a given point-of-care location, thepredetermined minimum inventory level for that location can be set. Forpurposes of illustration and not limitation, if the ambient shelf-lifeof the device is two weeks, the predetermined minimum inventory levelcan be set to one week. However, those of ordinary skill in the art willrecognize that the predetermined minimum inventory level can be setbased on any one or combination of additional or alternative factorsthat are associated with the given point-of-care location, such as, forexample, a location's needs, device usage rate, the rate at whichdevices are wasted, the rate at which devices are transferred to otherlocations, and the like.

If it is determined that the number of devices 104 that are available tothe reading apparatus 102 is above the predetermined minimum inventorylevel, then no action is required (block 410). If it is determined thatthe number of devices 104 that are available to the reading apparatus102 is below the predetermined minimum inventory level, then the centralrepository 302 can request that additional devices 104 be dispatched sothat they can be made available to the reading apparatus 102 (block412). The additional devices 104 can be dispatched from within thehospital or from outside of the hospital. It may be desirable, as amatter of economy, that a first in, first out (FIFO) method be adopted,as this preserves the devices 104 with the longest remainingrefrigerated shelf-life in the central repository 302. Thus, accordingto exemplary embodiments, the consumption of devices 104 by the readingapparatus 102 can be monitored to ensure an adequate supply of devices104 for each reading apparatus 102.

According to an exemplary embodiment of the present invention, a uniqueidentification code can be associated with each reading apparatus 102.The unique identification code can be contained in each communication tothe central repository 302. The central repository 302 can containinformation in its database 312 that allows the central repository 302to identify the location of a specific reading apparatus 102. Forexample, the central repository 302 can recognize, based on identifyinginformation (e.g., Internet Protocol (IP) address) contained within thedatabase 312, the specific infrared link, network port, or othercommunication connection that is used by the reading apparatus 102,thereby identifying the location of the reading apparatus 102. Thus, thecentral repository 302 can track the inventory levels in eachdepartment's local inventory 305. When devices 104 are dispatched to agiven department, one or more of the reading apparatus 102 in thatdepartment can be used to scan the new inventory.

According to exemplary embodiments of the present invention, initiationof the dispatch of the devices 104 and other consumable items from thecentral repository 302 to the individual departments can be prompted bysending an instruction for dispatch by a hospital's consumablesmanagement system. This can be, for example, an e-mail communication topersonnel in the central repository 302, an automated dispatchinstruction where inventory management at the central repository 302 isautomated and under computer control, a display message on the computerscreen of the management system, or any other form of communication ofan instruction typical of a hospital's consumables management system. Itwill be apparent to one skilled in the art that the degree of automationand computer control will vary between these institutions. Thus, theexact embodiment of the dispatch initiation is dependent upon the needs,budget, existing management system infrastructure, and the like of thehospital.

According to exemplary embodiments, the central depository 302determines whether the number of devices 104 in local inventory 305 isadequate for reading apparatus 102. However, it should be appreciatedthat such a determination can be made by other computing systems, suchas by reading apparatus 102. It should also be appreciated that, while asingle reading apparatus 102 is shown in FIG. 3, multiple readingapparatus 102 can be included within the system 300, and specificallywithin a department sharing the local inventory 305 within the hospital.According to exemplary embodiments, the number of devices 104 that areavailable in the local inventory 305 for use by any of the readingapparatus 102 is monitored so that an adequate supply of devices 104 areavailable for use with each of the reading apparatus 102.

It should further be appreciated by persons of ordinary skill in the artthat the method of FIG. 4 is applicable to a variety of types of devices104, each of which is capable of being used for a different test. Thedevices 104 can include, for example, blood analysis devices, urineanalysis devices, serum analysis devices, plasma analysis devices,saliva analysis devices, cheek swab analysis devices, or any other typeof disposable diagnostic device that can be used for point-of-caresample testing. The central repository 302 can monitor the use ofparticular types of devices 104 and can dispatch further inventories ofthose particular devices 104. The method of FIG. 4 is also applicable toother types of consumable items as herein described. For example, in aneonatal intensive care unit (NICU), each device 104 may be used with aheel-stick device, a capillary collection device, a swab to clean thecollection site, a pair of latex gloves, and the like. In an emergencyroom, a device 104 for electrolytes may be used in conjunction with aswab, latex gloves, a needle-stick device, a vacutainer, a syringe, andthe like. Other combinations of consumable items would be evident tothose performing point-of-care testing. The inventory for the consumableitems can thus be effectively monitored according to exemplary methodsof the present invention. For example, when dispatching a given numberof devices 104 to the NICU, the system can also dispatch a given numberof heel-stick devices. Such a determination can be based on, forexample, a simple one-to-one relationship or a more complicatedalgorithmic function that accounts for wastage or alternative uses forthe consumable item. For example, an algorithm can be created for theinventory control system by tracking the utilization history of theseconsumable items versus a device 104.

It should further be appreciated by persons of ordinary skill in the artthat the local inventory 305 can contain devices 104 that arerefrigerated and that are maintained at ambient temperature. The devices104 can be identified as being refrigerated or ambient temperaturedevices (e.g., using their associated identifying information) so thatthe central repository 302 can maintain proper inventory control of eachtype of device 104.

Once the local inventory 305 has been inputted into the database 312(FIG. 3), the system 300 can provide a real-time or near real-timeestimate of remaining inventory in the local inventory 305, based onrecognizing a consumption of a device 104 or consumable item byreceiving an electronic notification from the reading apparatus 102 ofthe consumption, as described with reference to FIG. 4. Whileeffectively instantaneous communication and real-time estimates aredesirable, the high degree of portability of certain types ofpoint-of-care reading apparatus 102 means that the reading apparatus 102may be temporarily left at a location in which communication is notenabled. Furthermore, the reading apparatus 102 can run several devices104 while at a location. Accordingly, the RAM 318 or other computermemory of reading apparatus 102 is of sufficient size to allow storageof the device 104 results until a time that the use can be communicated.According to an exemplary embodiment, the RAM 318 can accommodate up to100 sets of results, although any number of sets of results can bestored in RAM 318, depending on the amount of memory used. Thus,exemplary embodiments of the present invention provide for real-timeupdates to inventory usage, as well as allow the storage of the usageinformation in the reading apparatus 102 until such time that thisinformation can be communicated or otherwise downloaded to, for example,the central repository 302.

The system 300 can also provide an on-demand estimate of remaininginventory, based on analyzing data that has been compiled into thedatabase 312. These results can be displayed, for example, on thecentral data station, at the LIS, at the central repository 102 and onthe user interface 324 of each individual reading apparatus 102. Theresults display can also include a visual or audible flag or warningwhen estimated inventory falls to, near or below a minimum defined, orpredetermined, level. The predetermined level can be set by individualdepartments or centrally within a hospital to provide for a moreefficient overall inventory control based on economic and clinicalconsiderations. These considerations are known in hospital management.

As was discussed previously, the devices 104 can have a finiteshelf-life. Accordingly, it is desirable to maintain an adequate supplyof devices 104 that have remaining shelf-life and replenish the localinventory 305 as the shelf-life of the devices 104 expire. FIG. 5 is aflow chart illustrating the steps for monitoring the shelf-life ofdevices 104 and replenishing the local inventory 305, in accordance withan exemplary embodiment of the present invention. Initially, timestampinformation can be entered into the database 312 for the devices 104that are associated with the local inventory 305 (block 502). Thetimestamp information can be entered either manually by an operator orelectronically, for example, through bar-code reading at the time thedevices 104 are entered into the local inventory 305 and communicated tothe central repository 302. The timestamp information can be maintainedin the database 312 of the central repository 302. The timestampinformation can indicate when the devices 104 were added to the localinventory 305 (i.e., creation date) or when the shelf-life of thedevices 104 will expire (i.e., expiration date). The central repository302 can compare the timestamp database entries with the currenttimestamp (i.e., the current time) (block 504). If it is determined thatthe devices 104 have not expired (block 506), i.e., the currenttimestamp is before the expiration date of the devices 104, then thecentral repository 302 can continue to monitor the timestamp databaseentries and control is returned to step 504. If it is determined thatthe devices 104 have expired (block 506), i.e., the current timestamp isafter the expiration date of the devices 104, then the devices 104 canbe removed from the local inventory 305 (block 508), both physically andfrom the computer record of their inventory.

It is then determined if the number of devices 104 in the localinventory 305, after the expired devices 104 have been removed, is lessthan the predetermined number of devices 104 for the local inventory 305(block 510). If it is determined that the number of devices 104 in thelocal inventory 305 is above the predetermined number of devices 104,then control is returned to step 504. If it is determined that thenumber of devices 104 in the local inventory 305 is below thepredetermined number of devices 104, then the central repository 302 candispatch additional devices 104 to replenish the local inventory 305 sothat the number of devices 104 exceeds the predetermined minimum numberof devices 104 (block 512). Control is then returned to step 504, wherethe monitoring of the timestamp database entries continues. To providefor economically-efficient consumption of the devices 104, the localinventories 305 can be set to an adequate level to meet demand, but alsoat a level in which the number of devices 104 that reach theirexpiration date is reduced or minimized. The number of devices 104contained within the local inventories 305 can be monitored based onusage so as to dynamically reallocate the number of devices 104 amongthe local inventories 305 based on trends in usage.

As discussed previously, FIG. 4 illustrates how the devices 104 aredispatched to the local inventory 305 from the central repository 302.FIG. 6 is a block diagram illustrating a system 600, including multiplecentral data stations 604, 606 and 608, wherein the devices 104 aredistributed between the departments that are controlled by the centraldata stations 604, 606 and 608, in accordance with exemplary embodimentsof the present invention. The system 600 includes a central repository302, a central data station 604 for department X, a central data station606 for department Y and a central data station 608 for department Z.However, the system 600 can include any number of central data stations.A local inventory 610 is associated with central data station 604, alocal inventory 612 is associated with central data station 606 and alocal inventory 614 is associated with central data station 606,although any number of local inventories can be associated with eachcentral data station. Local inventories 610, 612 and 614 can contain anynumber of devices 104. For purposes of illustration and not limitation,in the system 600 depicted in FIG. 6, local inventory 610 includes threedevices 104, local inventory 612 includes two devices 104, and localinventory 614 does not include any devices 104.

The central data stations 604, 606 and 608 can provide connectivitybetween individual reading apparatus 102 and central locations, such as,for example, a LIS or HIS, and device 104 and central repositories 302.The central data stations 604, 606, and 608 can be connected with thevarious system constituents using any type of communications connectionthat is capable of transmitting and receiving electronic information,such as, for example, an Ethernet connection or other computer networkconnection. The central data stations 604, 606 and 608 can optionallyprovide a direct link back to a vendor's information system, for examplevia the Internet, a dial-up connection or other direct or indirectcommunication link, or through the LIS, HIS, or central repository 302.Such an exemplary embodiment can provide for automated re-ordering ofdevices 104 to maintain the predetermined levels of inventory at thehospital's central repository 302, and allow the vendor to forecastdemand and adequately plan the manufacture of the devices 104.

In an emergency situation, the inventory level at the central repository302 or individual locations can fall below that necessary to meet thenormal demand based on the predetermined levels for each department.Thus, the system according to exemplary embodiments of the presentinvention can automatically adjust the predetermined inventory levels ineach department based on various criteria. One exemplary criterion wouldbe, for example, to distribute devices 104 preferentially to thedepartments that treat patients with highest acuity. Other similar suchcriteria can be used.

In certain emergency circumstances, the system 600 can initiate transferof devices 104 from one department or local inventory to another,despite these devices 104 having already been moved out of the centralrepository 302. For example, where a hospital ER is dealing with a majoraccident, the devices 104 useful for the triage of patients can beredistributed to the emergency room. In such a situation, a flaggedmessage can be sent from the central repository 302 to the central datastations of departments other than the ER to initiate re-dispatch. Themethod of redistribution of devices 104 can also be extended to otherconsumable items used in connection with the devices 104, such that theconsumable items can be transferred between departments when necessityarises. Such redistribution of inventory enables the hospital to managethese resources in an efficient manner.

FIG. 7 is a flow chart illustrating the steps for determining whether tore-dispatch devices 104, in accordance with an exemplary embodiment ofthe present invention. The central repository 302 can monitor device 104use and/or expiration (block 702). Thus, the central repository 302attempts to maintain the local inventory levels above the predeterminedinventory level. The central repository 302 can receive messages from,for example, central data stations 604, 606 and 608. If a message isreceived, the central repository 302 can determine if the messagecontains an emergency flag (block 704). If the message does not containan emergency flag, the control returns to block 702. If the message doescontain an emergency flag, then the central repository 302 initiates are-dispatch from amongst the local inventories (block 706), thusmaintaining the local inventory level above the predetermined inventorylevels.

According to another exemplary embodiment of the present invention, thecentral repository 302 can be used to control and dynamically modify thepredetermined level of inventories 610, 612 and 614 for each department.The central repository 302 can be in direct or indirect communicationwith a vendor information system (not shown), in which the vendorinformation system is responsible for providing devices 104 and,optionally, other consumables to the hospital. The central repository302 can be connected to the vendor information system through humanintervention, i.e., verbal communication, but preferably is connectedvia automated computer-controlled processes, such as, for example, acomputer connection (e.g., a dial-up connection, an Internet or otherdirect or indirect network connection using hard-wired, infrared,optical, wireless or any other form of communication medium that allowsfor the transfer of electronic information).

The initial predetermined levels of inventory and subsequentmodifications can be based on variations in demand between department,the acuity of the patients in the departments, or even an emergencysituation, such as, for example, a hospital power failure emergency, atransportation emergency affecting the supply of devices 104 to thehospital, and the like.

Because devices 104 expire within a time period after being placed in anambient temperature setting, it is desirable to maintain thepredetermined inventory level based on actual usage. For example, if adepartment is not using its allocated devices 104 within the ambient orroom temperature storage period, then remaining devices 104 will bewasted. FIG. 8 is a flow chart illustrating the steps for re-dispatchingthe devices 104 between local inventories 610 to reduce excess devices104, in accordance with exemplary embodiments of the present invention.The device 104 usage rate is monitored (block 802). The monitoring canbe performed by the central repository 302, the reading apparatus 102,or any other computing system. Based on the monitored device 104 usagerate, it can be determined whether any devices 104 will expire, i.e.,will not be used before the room temperature or ambient storage time haselapsed (block 804). If devices 104 will not expire, then the device 104usage rate is again monitored, and control returns to block 802. Ifdevices 104 will expire, then the predetermined inventory level for thedepartment can be lowered to reflect a level that is more appropriatebased on the actual usage (block 806). Then, it can be determined whereadditional devices 104 (i.e., the devices 104 that will expire) can beused prior to their expiration (block 808). The excess devices 104 canbe sent to another department where they can be used prior to theirexpiration (block 810). Finally, the actual inventory level of theinitial department is adjusted to reflect that the sent devices 104 areno longer available for consumption within the initial department (block812). Thus, according to exemplary embodiments of the present invention,rather than sending new devices 104 to a department and allowing otherdevices 104 to expire, devices 104 that are to expire are used and wasteis reduced.

According to an alternative exemplary embodiment, by recognizing thatdevices 104 in the local inventory (e.g., local inventory 610) haveexpired, a waste rate can be computed. Specifically, because somedevices 104 were contained within the local inventory 610 and were notused because they expired, they were thus wasted. By comparing thenumber of devices 104 that were dispatched to the local inventory 610and the number of devices 104 that were used, the number of devices 104that were wasted (i.e., not used and expired) can be determined. Basedon the waste rate calculation, the predetermined local inventory levelcan be recalculated to reduce or otherwise modify the waste rate. Thenew predetermined local inventory level can then be updated in, forexample, the database 312 of the central repository 302.

According to another exemplary embodiment of the present invention, itis desirable to make certain devices 104 unavailable for use. Forexample, if a device 104 has expired due to having exceeded the roomtemperature or ambient storage time, the device 104 should not be used.FIG. 9 illustrates a flow chart for “locking out” devices 104, inaccordance with exemplary embodiments of the present invention.Initially, an indication of when certain devices 104 have been removedfrom the refrigerator is provided to the reading apparatus 102 (block902). Based on the indication, the reading apparatus 102 can determinewhen the removed devices 104 will expire due to exposure to ambient orroom temperature. Such a determination can be based on directinformation (e.g., the removed devices 104 will expire on a particulardate), or computed information (e.g., the removed devices 104 willexpire a certain amount of time from the date that they were removedfrom the refrigerator, depending on factors such as, for example, theactual ambient or room temperature). It can then be determined whetherthe ambient or room temperature timing for the removed devices 104 haselapsed (block 904). If the ambient or room temperature timing has notelapsed, then control returns to block 904 and the reading apparatus 102continues to monitor whether the ambient or room temperature timing haselapsed. If the ambient or room temperature timing has elapsed, then thereading apparatus 102 locks out the expired devices 104 (block 906).Because the expired devices 104 are locked out, the expired devices 104are not used. Thus, exemplary embodiments of the present invention canprevent devices 104 from being used that have expired.

The steps of a computer program as illustrated in FIGS. 4, 5 and 7-9 forcontrolling an inventory of a plurality of point-of-care diagnosticdevices can be embodied in any computer-readable medium for use by or inconnection with an instruction execution system, apparatus, or device,such as a computer-based system, processor-containing system, or othersystem that can fetch the instructions from the instruction executionsystem, apparatus, or device and execute the instructions. As usedherein, a “computer-readable medium” can be any means that can contain,store, communicate, propagate, or transport the program for use by or inconnection with the instruction execution system, apparatus, or device.The computer-readable medium can be, for example but not limited to, anelectronic, magnetic, optical, electromagnetic, infrared, orsemiconductor system, apparatus, device, or propagation medium. Morespecific examples (a non-exhaustive list) of the computer-readablemedium can include the following: an electrical connection having one ormore wires, a portable computer diskette, a random access memory (RAM),a read-only memory (ROM), an erasable programmable read-only memory(EPROM or Flash memory), an optical fiber, and a portable compact discread-only memory (CDROM).

It will be appreciated by those of ordinary skill in the art that thepresent invention can be embodied in various specific forms withoutdeparting from the spirit or essential characteristics thereof. Thepresently disclosed embodiments are considered in all respects to beillustrative and not restrictive. For example, it is to be understoodthat the present invention is applicable to other methods and apparatusfor inventory management in a point-of-care system beyond sample testingdevices. The scope of the invention is indicated by the appended claims,rather than the foregoing description, and all changes that come withinthe meaning and range of equivalence thereof are intended to beembraced.

All United States patents and patent applications, foreign patents andpatent applications, and publications discussed above are herebyincorporated by reference herein in their entireties to the same extentas if each individual patent, patent application, or publication wasspecifically and individually indicated to be incorporated by referencein its entirety.

What is claimed is:
 1. A point of care testing system, comprising: adisposable device comprising: a port configured to receive a patientsample; analytical elements including electrodes or optics for sensinganalytes within said patient sample; and a time and temperature sensorcomprising temperature-sensing circuitry configured to: provide a codeor signal associated with the disposable device that indicates a firsttime at which the disposable device has been moved from a refrigeratedstorage condition to an ambient storage condition; monitor a temperatureof the device at the ambient storage condition prior to the disposabledevice receiving the patient sample; determine whether the temperaturehas remained below, above, or within a predetermined temperature range;and in response to determining that the temperature has remained belowor above the predetermined temperature range, increase or decrease,respectively, a predetermined shelf life of the device by apredetermined amount of time that is dependent upon the temperature togenerate a modified shelf life; an analyzer comprising: a port configureto receive the disposable device; and a processor and a memory storingprogram instructions, wherein the program instructions when operated onby the processor, cause the processor to perform operations comprising:obtain the code and the modified shelf life from the disposable device;determine a second time when the disposable device will expire due tothe temperature of the device at the ambient storage condition based onthe code and the modified shelf life; determine whether the second timehas elapsed prior to use of the disposable device to determine whetherthe modified shelf life of the disposable device is exceeded; and whenthe second time has elapsed, lock out the disposable device such thatthe disposable device is prevented from being used.
 2. The device ofclaim 1, wherein the predetermined shelf life is a finite ambienttemperature shelf life that is dependent upon an ambient temperature inwhich the disposable device is stored.
 3. The device of claim 2, whereinsaid finite ambient temperature shelf life is from about 3 days to 3months.
 4. The device of claim 1, wherein the time and temperaturesensor further comprises a chemical component, a liquid crystal, amechanical device, a threshold device, or combinations thereof.
 5. Thedevice of claim 1, wherein the patient sample comprises blood, plasma,serum, interstitial fluid, spinal fluid, urine, bodily secretions orcombinations thereof.
 6. The device of claim 1, wherein the disposabledevice is a blood analysis device, a urine analysis device, a serumanalysis device, a plasma analysis device, a saliva analysis device, acheek swab analysis device, or a diagnostic device.